midterm Flashcards
1
Q
what is species richness
A
number of species in a defined region
2
Q
how does species richness respond with increased area
A
it increases
3
Q
where is species richness the highest
A
tropics
4
Q
what is a driver
A
factors that may explain changes in biodiversity
5
Q
what is a predictor
A
environmental variables that can be measured and correlated with diversity back to drivers
6
Q
what is genetic diversity
A
hoe much genetic variation there is in a population
7
Q
what is functional diversity
A
component of diversity that influences ecosystem dynamics, stability, productivity, nutrient balance, and other aspects of ecosystem functioning
8
Q
what is phylogenetic variation
A
how much distinct evolutionary history is present in a community
9
Q
what is alpha diversity
A
number of species found at a local site
10
Q
what is gamma diversity
A
measure of species richness in a region
11
Q
what is beta diversity
A
a measure of the difference in species composition or turnover between two or more habitats or local sites in a region
12
Q
what is a region
A
large in spatial scale and containing many habitats and communities
13
Q
what is a biogeographic region / realm
A
biologically and climatically distinct regions at major geographic boundaries
14
Q
what is a regional species pool
A
species likely to colonize a local community
15
Q
how does a more uneven distribution of abundance affect alpha and beta
A
alpha decrease
beta increase
16
Q
how do spatially clumped individuals within a species effect alpha and beta diversity
A
alpha decrease
beta increase
17
Q
how does a higher gamma diversity effect beta and alpha
A
increase both
18
Q
how does a smaller plot area effect alpha and beta
A
alpha decrease
beta increase
19
Q
how does a higher density of individuals influence alpha and beta
A
alpha increase
beta decrease
20
Q
factors that change alpha and beta diversity
A
how uneven the distribution is
if the individuals of a species are clumped or spatially random
total regional gamma richness
density of individuals across the region
21
Q
what is a driver
A
factors that may explain patterns in diversity
22
Q
what is a predictor
A
environmental variables that can be measured and correlated with diversity and related back to drivers
23
Q
what is a mechanism
A
process that lead to the pattern
24
Q
what is evapotranspiration
A
the sum of evaporation from the land surface plus transpiration from plants
shows how much primary productivity
25
what is diversification
speciation - extinction = diversification
26
how does species richness change as area increases
it increases
27
what are the hypotheses of the latitudinal diversity gradient
- null model
- ecological hypothesis
- historical hypothesis
- evolutionary hypothesis
28
what is the null model hypothesis of ldg
mid domain effect: ranges random and more likely to overlap in middle
29
what is the ecological hypothesis of ldg
climate sets limits for species richness
30
what is the historical hypothesis of ldg
- area: tropics have more area
- larger areas can support larger populations = less extinction
- larger areas have more barriers = more speciation
-time integrated area hypothesis: tropics have suffered fewer harsh climatic events so they have had more time to speciate
31
what is the evolutionary hypothesis of ldg
- climate stability hypothesis: tropical climate is predictable and mild allowing for greater speciation and smaller niches = more species
while higher latitudes have unpredictable climates creating larger niches = less species = more extinction
- evolutionary speed theory : higher temperature and solar radiation = more mutations and faster growth rate = faster speciation rate
- biotic interactions hypothesis: biotic factors have a stronger selective force than abiotic factors
32
what is tropical niche conservatism
tendency of lineages to originate in tropics and to remain tropical due to the relations of climatic niches over evolutionary time
33
why does species richness increase with larger areas
larger areas have more habitats/niches/diversity so can support more species
larger areas can also support more genetic variation, reduce the chances of a catastrophic event from wiping out the populations, larger area= larger target (more colonization)
34
what is the target effect
bigger area= more colonization
35
what is the rescue effect
isolation influences extinction
more colonization/immigrants increase the fitness of an island
36
what is the small island effect
below a certain point species stop obeying the species richness to area relatioonship
37
what factors effect z
island vs mainland: isolation
dispersal distance of taxonomic group
latitude
38
how does z effected when its on an island vs mainland
higher on islands
39
how is z effected by dispersal ability
lower in species with greater ability to disperse
40
how is z effected by ldg
higher in tropics
41
what relationship does z have with dispersal abilities
inverse 1
42
what are stabilizing mechanisms
spatial variantion in environment and resource partitioning
temporal variation
competition - colonization tradeoff
predators
43
what is spatial variation in the environment/ resource partitioning
species have a preference for certain habitat/environmental conditions
often the species that preform best in optimal conditions are least tolerant
species can forage in different parts of same area (ex: foraging in different parts of tree)
44
what is temporal variation
seasons changing in environment effect the available nutrient levels as well as how they're dispersed
certain species are better/worse at certain nutrient levels
storage effect
45
what is the storage effect
environmental fluctuations effect one species (with lower abundance) disproportionately
though as its density decreases the competition decreases
46
what is the competition- colonization prediction
how species that are better at colonizing are less competitive
and more competitive species are slower at colonizing
47
what is a fugitive species
good at colonizing but not as competitive
48
how can predators stabilize prey populations
preying on most competitive species (ex:starfish example)
prey- switching (ex generalists)
49
what is a gleamer
out compete at low nutrient levels
50
what is an opportunist
out compete at higher nutrient levels
51
what is interference competition
occurs directly between individuals
individual directly alters the resource attaining behaviour of another individual
52
what is exploitative competition
indirect
| use of resources by one individual decreases amount available for others
53
what is competitive exclusion principle
two species with identical niches cannot coexist indefinitely
54
what is the law of limiting similarity
the existence of a maximum level of niche overlap to allow for continued coexistence
55
what is interspecific competition
competition between individuals of different species
56
what is intraspecific competition
competition between individuals of same species
57
when is coexistence possible?
when intraspecific competition is greater than interspecific competition
58
what is R*
minimum equilibrium resource level required to maintain a population
59
can 2 species coexist if resource levels are constant
no, species with lower r* wins
60
is coexistence possible if resource levels fluctuate
yes
61
does coexistence require tradeoffs
yes
62
what do organisms try to feed on
most profitable food source
63
what are more efficient specialists or generalists
specialists
64
what is optimal foraging theory
predators adjust their behaviour in response to variation in prey abundance
65
What are consumptive effects
lethal effects
occur when predator feeds directly on prey
66
what are non-consumptive effects
behavioural changes in prey in response to predation
67
what are examples of non consumptive effects
changes in morphology
changes in behaviour
changes in life history (ex timing of metamorphosis)
changes in stress levels
68
why do changes in response to prey have tradeoffs
investments in defence cannot be used for reproduction
| changes in foraging behaviour may have foraging costs
69
what determine how predators influence a community
predator preferences and competitive ability of prey
70
what is a functional response
change in predation in response to changing prey density
| individual response
71
what is a numerical response
change in reproductive rate with changing prey density
| population response
72
what are faster functional or numerical responses
functional
73
what is a type one functional response
linear increase in consumption rate as food densities rise until reaching a maximum consumption rate
slope = consumer's attack rate
74
what is a type 2 functional response
rate of prey consumption rises as prey density increases, though eventually plateaus where rate of consumption remains constant, no matter the increase in prey density
reaches saturation gradually unlike type one which is linear
75
what is a type 3 functional response
occur when predators increase their activity with increasing prey, eventually plateauing as prey densities start to decline
76
what type of functional response do generalists have
type 3
77
what type of functional response do specialist predators have
type 2
78
what is a carrying capacity
K
maximum population size supported by the available resources in an environment
79
what is a specialist
predator that feeds on a single prey type
80
what is a generalist
predators that switch between prey types
81
what does Lotka Volterra model assume
prey populations grow exponentially
type 1 functional response
predator growth is independent of predator density
82
what does Lotka Volterra model show
simplest model describing population dynamics of a single predator species feeding on a single prey species
produces coupled cycles in predator prey relationships but is very unstable
83
what is the rosenzweig MacArthur model
incorporates carrying capacity into prey population of Lotka Volterra to make it more realistic type 2 response which makes isocline be humped
84
what does it mean of predator prey intersect is to the left of isocline
system changes can result in one or both species going extinct
85
what does it mean of predator prey intersect is to the right of isocline
system will return back to equilibrium after deviation
86
what is an aggregative response
immigration and emigration rates
87
what is a demographic response
reproduction and mortality rates
88
what does aggregative + demographic responses =
numerical response
89
what is the paradox of enrichment
increasing prey's carrying capacity will decrease stability of predator prey dynamics
90
when are predator prey systems most stable
when predator is inefficient
91
what is a grinnellian niche
the habitat requirements that allow a species to persist and reproduce
92
what is a hutchinsonian niche
expanded grinellian niche by separating habitat into specific resources
and considered how species interact
93
what is a eltonian niche
an animals place in the biotic environment
ex: its relation to food and enemies
94
what is a sequential breakage hypothesis
available niche is slowly divided among species as they arrive
95
what is a broken stick model
all species arrive at same time and resources are divided randomly
96
what is a geometric series
each successive species takes up a fixed fraction of available niche space
